Grate structure



May 19, 1925.

D. S. VAN WAGENEN GRATE STRUCTURE 2 Sheets-Sheet 1 Filed Feb, 23, 1921 May 19,1925. 1,538,761

D. s. VAN WAGENEN GRATE STRUCTURE Filed Feb, 2:5, 1921 2 Sheets-Sheet 2 Cal Patented May 19, 1925.

UNITED STATES 1,538,761 PATENT OFFICE.

DONALD S. VAN WAGENEN, 0F BROOKLYN, NEW YORK, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO BENJAMIN F. WATKINS, OF PHILADELPHIA, PENN- SYLVANIA.

GRATE STRUCTURE.

Application filed February 23, 1921.

To all to 710m it may concern:

Be it known that I, DONALD S. VAN AG- nNnN, a citizen of the United States, residing in Brooklyn, New York, have invented Improvements in Grate Structures, of which the following is a specification.

This invention relates to improvements in grate structures of the type employed with forced drafts and comprising a series of parallel hollow grate elements, the top or fuel supporting surfaces of which have suitable apertures or slits therein for the passage of air which is forced into the elements from a suitable external source. These hollow elements are ordinarily connected with a common air duct or manifold into which air is forced from a blower or fan, the air entering the respective ducts in equal volumes and being thereby equally distributed through the entire surface of the fuel upon the grate.

One object of my invention is to provide means for giving an even distribution of draft air over the entire area of the fuel and for eliminating all dead spaces in which the fuel is left unburnt because of a lack of draft air.

Another object is to provide a sectional construction of the upperor fuel supporting portions of the grate structure having eertain improved characteristics of adjustment and whereby repairs or replacements of any particular portion of the grate which has become damaged, may be made both easily and cheaply.

A further object is to provide a sectional construction of the lower or base portion of the grate elements whereby manufacture of the said elements in different lengths to suit boilers of various sizes is made comparatively simple and the necessity for the employment of an excessive number of molds eliminated.

A still further object is to provide means for introducing into the fire box at a point above the surface of the fuel superheated air which will aid in the combustion and in the consumption of the combustible gases, at large portion of which under ordinary conditions is swept unburnt from the furnace.

It is further desired to provide a means whereby the fuel supporting members may be applied independently of the base portions to boilers in which the fire boxes and openings.

Serial No, 447,199.

ash pits are such as to prohibit installation of the entire structure.

The invention will be more readily understood from the attached drawings, in which:

Fig. 1 is a horizontal sectional view of sufficient of a fire box of a boiler to illustrate my invention as applied thereto;

Fig. 2 is a longitudinal section taken on the line 22, Fig. 1;

Fig. 3 is a transverse section taken on the line 3-3, Fig. 2;

Fig. 4 is an enlarged section of a plurality of the grate bar sections;

Fig. 5 is a perspective view of one of the base structures which support the grate bar sections;

Fig. 6 is a perspective View of one of the grate bar sections;

' Fig. 7 is a perspective view of a modification of one of the grate bar sections;

Fig, 8 is a section of the air duct showing the damper and'its associated plunger and rod; v

Fig. 9 is a perspective view of the forward end of the damper rod, showing its handle and locking notches; and

Figs. 10, 11 and 12 are transverse sectionalviews of various modifications within the scope of my invention.

With reference to the drawings, 1 indicates the base or channel portion of oneof the elements of my grate structure, said base portion being in the form of a hollow trough, made in the present instance in sections 2 and 3 of substantially equal lengths, said sections each having at the forward end thereof an opening in the bottom which in each case is adapted normally to be closed by slides 4. and 5 respectively, said slides being suitably joined together by means, in

the present instance, of a connecting rod 6, and the said slide on the forward section having a downwardly depending arm 7 by means of which the slides may be moved longitudinally to open or close the said In the present instance, I have shown attached to the said arm 7, an operating rod 7 extending through the front wall of the ash'pit, and said rod being jointed so that the outer end may hang downwardly and thereby be disposed out of the way when the said slides are in the closed position.

The said sections 2 and 3 are formed in the present instance with a shoulder 8 extending longitudinally at each side thereof, upon which shoulders are adapted to rest, the legs 9 and 10 of a series of abutting grate sections 11, one of said sections being most clearly illustrated in Fig. 6 of the drawings. These sections comprise the said legs 9 and 10 between which extends abridge portion 12, preferably arched out at the under side, said bridge portion lying laterally across the top of the saidbase portion. The said legs extend atone side beyond the side surface of the said bridge portion and the said legs, after they join to the said bridge portion, are tapered away outwardly towards the top as indicated at 13, so that the said projecting portion of the legs at the top surface thereof is merely a line, as shown in Fig. 6.

This formationmay be modified so that the said projecting portion of the legsis tapered away to end at a point below the top surface of the bridge portion, as shown 111 Fig. 7. These extensions 9 and 10? of the said legs-constitute stops whereby the adjacent and abutting grate sections are spacedapart a predetermined amount so that a slot is formed between each section. It is further found desirable that the bridge portions of these grate sections taper inwardly from the top surface to the bottom so that the dividingslots between the said sections are wider on the under side than .at the top surface as illustrated in Fig. 4.

These interposed spaces or slots may bevaried if desired by increasing the thickness of the said leg extensions, and sections may be formed to give slots of any width desired, thereby accommodating the grate to any of a wide variety of fuels.

It is preferable in grates of thistype to have the portion of the grate surface which joins the front of the boiler elevated above the main portion of the grate surface. In order to accomplish this result the said grate sections 11 may be made with legs of dili'erent lengths so that the grate surface may rise at the front in a smooth incline, as most clearly shown in Fig. 2. It will beseen with this construction the said slots or openings between the grate sections extend completely across the whole width of the section, and any air forced from the inside of the elements upwardly through the said slots will accordingly be distributed through the entire body of fuel from which all dead spaces are eliminated.

In Fig. 12, I have shown a modified form of the structure, in which the legs are made wider at the bottom than at the top. The outer edges of the legs may remain, in this instance, perpendicular to the bottomthereof, ivhile the inner edges of the legs extend inwardly toward the bottom at an angle. to the perpendicular. The upper edges of the said base portions which extend above the supporting shoulders flare outwardly at the sides, sothat it is necessary, in placing the fuel supporting sections upon the base sections, to slide them on from one end, and the'removal of the said topsections by lifting them away from the base sections is, in this manner, prevented. This form of structure may be found desirable under certain conditions, and modification falls within the scope of my invention.

The base sections of the grate structure, as previously stated, are made in sections, in the present instance of substantially equal lengths, and these two sections are so connected that the union is telescopic in nature, a portion of onesection fitting into the other, in the manner illustrated in Fig. 5and the arrangement is such that although the two portions telescope the said shoulders 8 which extend along the sides for the purpose of supporting the upper grate sections, form a substantially unbroken line from the extreme front of the grate to the rear. It is clear that with this type of structure the length ofthe sections may be Varied with little trouble to give an overall length of the grate structure suiting any conditions that may be met with. F urthermore instead of having to supply a great variety of patterns, a separate set for each set of different grate structures, it is only required to have two main sections which together form a grate of a minimum length, with patterns for forming extensions of differing lengths, so that the grate sections may be lengthened as desired. At most this method requires merely the provision of different lengths of patterns for extensions,

the main portions of the grate structure being standardized.

In applying this grate to a boiler or the like, it is merely necessary to support the said, grate sections in the fire box in any suitable manner, as by means of brackets or beams secured to the front wall at the front and a suitable attachment to the bridge wall 21 at the rear and intermediate the front and rear upon one or more suitable cross beams 22.

In the preferred construction the rear base sections ofthe grate elements are mounted in openings in the front side of the said bridge Wall which latter is made hollow and the extreme rearward end of the base section is also made in the form of a duct whereby air introduced'or forced into the interior chamber ofthe said bridge wall will have free access through the said openings to the interior of the said elements, the said hollow bridge wall constituting a manifold for the said elements. In the present instance I have shown a blower or fan 23 from which, as a source, draft air is led through a duct 24: to the interior of the bridge wall. A damper, or dampers, 28 may be provided at the rear of the said sections for breaking the communication between the said bridge wall duct and the interior of the respective grate elements. In the present instance I have shown an integral damper 28 pivotally mounted at the rear of the grate elements and operated by a single rod 29 which may extend forwardly between the grate elements, as most clearly shown in Fig. 3, said connecting rod being equipped with means such as the notches 29 for retaining it in different positions whereby the said damper may be elevated or lowered to regulate the amount of air passing from the duct within the bridge wall into the interior of the grate elements.

In order that there may be no leakage of air from inside the bridge wall through the aperture 31 therein through which the rod .29 extends, I provide, as shown in Fig. 8, a

cylindrical liner 32 for said hole, in which is mounted and adapted to slide a plunger 33. The inner extremity of the rod 29 is attached to one end of the plunger, while a .link 34. is pivotally attached to the opposite end of the plunger and to the damper. This arrangement permits free manipulation of the damper by means of the rod 29, while preventing leakage of the draft air.

In the preferred form, which is illustrated in Fig. 2, I form in the top of the bridge wall a series of restricted openings or ducts 30, said openings extending diagonally upwardly and forwardly towards the front of the boiler and being so disposed that jets of air are ejected from the duct within the bridge wall, forwardly over the surface of the fuel in the fire box. This air in passing through the bridge wall, becoming superheated, since the said bridge wall is heat ed to a high temperature by contact with the incandescent fuel and the hot gases which pass thereover, so that the air in passing therethrough and being superheated as stated, is in condition to assist in the combustion of the unconsumed gases which invariably form within the boilers and which are often swept through the stack without having their heat content utilized.

It will be noticed that a lug or projection 23 extends downwardly from the under side of the rear base section into a recess in the bridge wall whereby the said rear section is held against possible longitudinal movement with respect to the bridge wall. In installing the grate structure furthern'iore, the two base sesctions are not placed with their adjoining ends tightly together, there being provided in this manner a certain amount of leeway for expansion.

\Vhere on account of the construction of the boiler it is impossible to install the grate structure as a whole, I am enabled by extending suitably spaced cross-beams 35 across the fire box to mount thereon the upper or fuel supporting portions 11, and by then forcing air into the ash pit, it is possible to obtain an effect substantially equal in degree to that obtained in the complete structure. In Fig. 11 I illustrate a special beam 35 designed for supporting the portions 11.

The advantages accruing to the grate structure that I have described are manifold. By means of the sectional construction of the upper portion of the grate, a considerable saving in the material required and in the cost of manufacture is obtained, with a much more efficient structure. There is, for example when breakage occurs in the top portion of the grate, no necessity for replacing any more than just those particular sections affected, whereas in grate structures of the usual form, it is necessary to replace a comparatively large casting. It is further possible, by means of varying the thickness of the extensions of the lugs which space the sections apart, to vary the width of the draft'opening to correspond with any par ticular kind of fuel that is to be employed.

The advantages of the sectional construction of the lower portion of the grate structure have already been stated, this method of construction creating a substantial saving in the cost of manufacture and in the ease of adapting the grate structure to any sized grate. There is a decided advantage also in supporting the rear end of the grate structure in a side opening in the bridge wall instead of as in the usual construction upon the top of the grate wall, this advantage residing in the fact that the air is introduced into the grate elements in a longi tudinal direction, and it is therefore distributed more evenly in the elements. In this connection, the use of the damper located and operable as shown, assists in directing the air into the elements in the proper longitudinal direction. By means also of the ducts extending through the top of the bridge wall, a supply of superheated air is provided which materially assists in combustion of the fuel and gases in the fire box.

I claim: I

1. In a grate structure, an element adaptinc ed to be placed side by side and end to end with like elements to form a fuel'supporting surface, said element having at each end and at the side a substantially wedge-shaped spacer lug the point of which projects upwardly and lies at the end edge of the element.

2. In a grate structure, an element adapted to be placed side by side and end to end with like elements to form a fuel-supporting surface, said element having at each end and projecting from the side of the element, a spacer lug diminishing in width toward the top of the element and terminating in line at the end of the element.

8. A grate element adapted for mounting side by side and end to end with like elements to form a fuel-supporting surface, said element having fiat end faces adapted to abut the end faces of said like elements, and a side spacer lug" at each end terminating at its top in a line lying in the plane of said end fac v 4. A grate element adapted for mounting side by side and end to end with like elements to form a fuel-supporting surface, said element having substantially flat top and end faces, and a spacer lug projecting from the side and at each end of the element and diminishing in width toward the top so as to terminate in a line which is substantially an extension of the top end edge of the element.

5. A grate element adapted for unounting side by side and end to end with like elements to form a fuel-supporting surface, said element having at each end a depending part or leg, and said legs and that portion of the element immediately: over the legs being of increased thickness and projecting beyond theside face of the element to form spacers, the said projecting portions decreasing in width toward the top of the element and terminating in a line at the extreme ends of the element.

6. A grate element adapted for mounting side by side and end to end with like elements to form a fuel-supporting surface, said element having substantially flat top and end faces, and a depending part at each end whose outer face corresponds substantially with the end face of the element and lies substantially normal to the top surface of the element, said depending parts and that portion of the element immediately thereover being of increased thickness and projecting beyond the face of the element and constituting spacer elements, and the said increased portions of the element decreasing in width toward the top of the element and terminating in a line coinciding with the end faces.

7 A grate element adapted to be mounted side by side and end to end with like elements to form a fuel-supporting surface, the end faces that abut the elements being flat, and spacer lugs at the ends of the elements projecting from the side and extending substantially to the-top or fuel-suppoiting surface and tapering at the top outwardly to the said end faces.

8. A grate element adapted for mounting side by side with like elements to form a fuel-supporting surface, said element comprising a substantially horizontal piece with spaced depending legs having a generally greater thickness than said horizontal and forming thereby lateral. extensions constitutingspacers for the horizontals of abutting elements, and said extensions taperingin width toward the top to prevent accumulations above the spacers.

9. A grate element adapted for mounting side by side with like elements to form afuel-supp'orting surface, said element comprising a substantially horizontal piece having spaced depending legs which with portions of said horizontal piece contiguous to said legs have a greater thickness than the main portion of the horizontal, said parts of'greater thickness constituting spacers for said main portions of the horizontals of abutting elements and tapering toward the tops thereof to prevent accun'uilations thereabove. I

10. A grate element adapted for mounting side by side with like elements to form a fuel-supporting surface, said element comirisin a substantiall horizontal iece hav- 2:

ing spaced depending legs which with portions of said horizontal piece have a greater thickness than the main portion of the horizontal, said parts of greater thickness constituting spacers for said main portions of the horizontals of abutting elements and tapering toward the tops thereof to prevent accumulations thereabove.

11. In a grate structure, the combination with spacedsupports, of a plurality of elements adapted for mounting side by side upon said supports to form a fuel-supporting surface, said elements each comprising a piece adapted to bridge said spaced sup ports and having depending legs adapted by engagement with said supports to retain the elements in position, said legs having a generally greater thickness than the bridge pieces and forming thereby lateral eXten sions constituting spacers for the horizontals of abutting elements, and said extensions tapering in width toward the top to prevent accumulations above the spacers.

12. In a grate structure, the combination with spaced supports, of a plurality of elements adapted for mounting side by side upon said supports to form a fuel-supporting surface, said elements each comprising a piece adapted to bridge said spaced supports and having depending legs which by engagement with said supports are adapted to retain the elements in position, said legs together with portions of said bridge pieces contiguous to said legs having a greater thickness than the main portion of the bridge piece, and said parts of greater thick ness constituting spacers for said main portions of the bridge pieces of abutting elements and tapering towardsthetop thereof to prevent accumulations thereabove. V

13. In a grate structure, the eomblnation with spaced supports, of a plurality of elements adapted for mounting side by side upon said supports to form a fuel-supporting surface, said elements each comprising a piece adapted to bridge said spaced supports and having depending legs which by engagement with said supports are adapted to retain the elements in position, said legs together with portions of said bridge pieces having a greater thickness than the main portion of the bridge piece, and said parts of greater thickness constituting spacers for saidimain portions of the bridge pieces of abutting elements and tapering towards the top thereof to prevent accumulations thereabove.

14. In a grate structure, the combination with spaced supports, of a plurality of elements adapted for mounting upon said supports side by side to form a fuel-supporting surface, said elements each comprising a piece adapted to bridge said spaced sup-' ports, and having depending legs adapted to extend down the outside of said supports and adapted thereby to retain the elements in position, said legs having a generally greater thickness than the bridge pieces and forming thereby lateral extensions constituting spacers for the bridge pieces of abutting elements, and said extensions tapering in width toward the top to prevent accumulations above the spacers.

15. In a grate structure, the combination with spaced supports, of a plurality of elements adapted for mounting side by side upon said supports to form a fuel-supporting surface, said elements each comprising a piece adapted to bridge said spaced supports and having depending legs adapted to ext-end down the outside of said supports and constituting the sole means for retaining the elements in position upon the sup ports, said supports and legs being such as to permit withdrawal of an element from the supports in a vertical direction, and portions of greater thickness upon said element forming lateral extensions constituting lugs for spacing apart the said bridge pieces of abutting elements, said extensions tapering toward the top to prevent accumulations thereabove.

DONALD S. VAN lVAGENEN. 

